Natural gas, as it comes from the ground, may contain impurities. One impurity that is often found in natural gas is sulfur, particularly sulfur in the form of H2S. It may be desirable to remove the sulfur from a natural gas stream because, for example, it may prematurely corrode pipelines and it also may act as a poison to catalysts in downstream processes. One method of removing sulfur from a natural gas process is the Claus Process. The Claus Process generally consists of several steps: (1) oxidizing a portion of the H2S to form some elemental sulfur and some SO2 and (2) reacting some of the remaining H2S and SO2 to form elemental sulfur and water. The sulfur produced in the Claus Process is generally produced at near atmospheric pressure (e.g., less than about 15 psig).
Another method of removing sulfur from a gas stream is through the direct partial oxidation of the H2S to produce water and elemental sulfur. Generally, in this partial oxidation process, a stream containing up to about 3% H2S is partially oxidized over a catalyst to produce, inter alia, elemental sulfur at elevated pressures (e.g., greater than about 15 psig). See generally, U.S. Pat. Nos. 5,271,907 and 6,099,819, incorporated herein by reference. The methods of processing sulfur at near atmospheric pressure may not work properly when handling elemental sulfur at elevated pressures. Additionally, other high pressure treatment processes may be capital intensive, may require many moveable parts, which may require frequent maintenance and/or possibly expose workers and operators to high pressure sulfur. Thus, there is a need for a process for processing sulfur at elevated pressures which alleviates or eliminates one or more of these concerns.